Starting clutch for motors



Dec. 3, 1929. 1 M. PERSONS STARTING CLUTCH FOR MOTORS Filed Maren so,1929 2 sheets-sheet 1 Dec. 3, 1929. L.. M. PERSONS STARTING CLUTCH FORMOTORS Fivled March 30, 1929 2 Sheets-Sheet 2 ffl/lll# ma l@ PatentedDec. 3, 1929 UNITED STATES PATENT OFFICE LAURENCE M. PERSONS, OF ST.LOUIS, MISSOURI, AISSIGNOR T0 EMERSON ELECTRIC MANUFACTURING CO., 0FCHICAGO, ILLINOIS, A CORPORATION OF MISSOURI STARTING CLUTCH non moronsApplication filed March 30, 1929. Serial No. 351,319.

My invention relates to a starting clutch for motors and has forparticular purpose the provision of a starting clutch or starting meansfor an induction motor. One object is to provide an automatic startingclutch and gearing for initiating the rotation of such a motor 'for thepurpose of obtaining a high starting torque with a low amperage. Anotherobject is the provision of such starting means which shall be effectiveat the starting of the motor but which shall be entirely withdrawn fromoperation after the rotor of the motor approaches normal speeds ofrotation. Another object is the provision of a starting clutch whichshall be noiseless and which shall have a maximum life or wear. Otherobjects will appear from time to time in the course of the specificationand claims. i i

I illustrate my invention more or less diagrammatically in theaccompanying drawing, wherein Figure l is an axial sectiong.

Figure 2 is a section on the line 2 2 of Figure l;

Figure 3 Figure l;

.Figure 4L is a section on the line fl4r of Figure l; and

Figure 5 is a section on the line 5-5 of is a section on the line 3-3 ofFigure 3. i

Like parts areindicated by like symbols throughout the specification anddrawings.

Referring for example to Figure l A generally indicates anysuitablemotor housing within which is contained, although not shown indetail, the rotor ot any suitable inductionmotor. The housing is shownas having an end wall A1, a centrally disposed portion A2 which mayenclose any suitable bearingmember for the stub shaft A3 of the motor.Adi indicates an abutment l flange formed at the end of the housingr A,and hav ing inset therein a frictional member or ring A5. A6 indicatesany suitable protectingr flange or sleeve extending axially outwardlyabout the gearing elsewhere herein described. It is indicated asseparate from the housing A but if desired it may be formed integralwith it.

Fixed upon the stub shaft A3 and held against rotation in relationthereto is thehub member B which may be pinned in position as by the pinB1. Mounted upon this hub member is the disc B2. Mounted for centriiugal movement in relation to said disc are the centrifugal shoes B3shown in side ele vation in Figure 3 and in section in Figures 3 and 5.f he shoes are indicated as segments containing the slots Bt throughwhich pass the screws B screwed into the disc B2 as at B6. The head BTof these screws set in enlargements Bs of the slots B, The slots beingformed and positioned as shown in Figure 8, it will be understood thatthe shoes B3 are constrained to outward movement, in response. to therotation of the disc B2 in opposite directions from the center ofrotation. They are normally constrained to inward position, for exampleby the springs B9, each spring being secured at one end to an abutmentB10, at one of the segments or shoes. In the structure as shown theshoes are constrained to inward position when the disc is not rotating,but may be moved to outward position in response to rotation of thedisc. Note that the shoes at their outer extension terminate in inclinedsurfaces B11.

Surrounding the end oi the stub shaft A3 outwardly beyond the hub B isthe bearing bushing C. Fositioned about said bushing is the sleeve C2about which is mounted the pulley C3 with its extension or hub Gt. C5indicates any suitable securing means for preventing rotation of thepulley C3. C indi Cates a disc secured against rotation in relation tothe sleeve C2 and provided about its periphery with a lateral extensionCT in which may be inset the frictional member CS adaptn ed to beopposed to the inclined surfaces B11 of the shoes or segments B3.vFurther secured to the portion C7 is the ring` C9 which may beconnected to it for example by the screws or bolts C10. It is providedwith a further extension generally indicated as C11.

This further extension C11 is indicated as inclined fromperpendicularity to the axis of rotation of the motor.

Mounted upon it are a plurality of stub shafts D herein shown as threein number and Vce screwthreaded into the ring or extension C as at D1.The heads D2 of each member D serve to constrain against aXial movementthe frictional driving rollers D3, each such roller having the inclinedperipheral bearing surface D4.

Mounted for rotation with the shaft A3 is the friction gear or membergenerally indicated asv E and including the hub E1 the fiangejE3projecting therefromy and the frictionmemberproper E3 Which may beformed of a plurality of sheets Eto-fA any suitable friction material,for examplev of fibrous'ma' tcrial. This friction materialterminates inthe inclined or beveled 'circumferential bearing surface E3.- E??indicates anysuitable Clamping ymemberwhich may be held againstftheseistripsifas by the screw E3, the layers being thereby clampedbetween the member E3 and thejlange E?. The hub member El is :providedaerith plurality of -cam surfaces herein "ind-icatedas d'i'ametricallyopposed cut away"portions EBihaving one straight face E andthe inclined{cam-face E19.- `But one of thesegcam members is -'shovvn. in VFigure 1and fit will ybe1uncilerstood that the second one is dametricallyopposedthereto and if it ap- .pefazedgontle drawing-would show an inclinationin the opposite direction, whereby the 'twoxcamysurfaces have fa;unitary action. -Thesecamrsurfaces larefadaptfed to be engaged :by teeXtend'i-ngends,ofapin'G mounted in .aiblo'ck 'G3 sl-idable `Within`tjhefaxialqaper tu'refG3fof theqshaft. A3. 1 The block G3 and the pinG.; are normally urged tothe left, as ,shown in Figure 1F, asV bythespringG3 Whicl is compressedbetween theblock G1 and the block G4f whichispinned by the pin'G3 passjinggthrough the securing terminal sleeve G6'vfthe-shaft. TheV sleeve 'G3 has the addi-- tionalgfunction `of'serving,T as 'astop lto limit fthe; out iard :movement `of the 'sleeveG3 with fIt Wi lf be realized that Whereas yI have de,- scribed andlshown (fi-practical and operative d'e,vi`ce, nevertnele'ss s many`changes may be "madefin size, shape, number and dispositionofpartsgxvithout,departing from the spirit of myfinvention. VI-Wish mydrawings to be takenvas in vabroad sense illustrative anddiagrammatieratherthan as limiting me tothe fspeeieidetailsr of.drive,fgearin'g' and the like. :s f The use andfoperation ofmy-invention are 'a'sfollowsz l v Y ,-Imthe nermaloperationfofthefdevice here,- ifn shown .f1 {prov-ide a jmfeeh anical substitute--fofr'oltai-ningovvith the .use of) a splitphase i induction motor,thecharaeteristics of a plane induction fmotor.-. (I am able -to start,`such a .motorgama minimum s amperage and obtain zusatisfactory',startingtorque. As soon as the rotor comes up to speed,the starting inearszisclrtout and themotor directly drives thedriNen;member,- pu1ley orthe like.

Referring,- for example to the structure described and shown herein,when rotation of the rotor and shaft A3 is initiated the initialrotation of the shaft A3 moves the pin G against the cam surfaces El@and urges the friction member geneally indicated as E, to the left, asshown in Figure 1, lts beveled surface E3 is thereby thrust intoengagement Withthe bevel surfaces D4 of the rollers D3 and thesesurfaces also engage the opposed frictional surface or member A3. The`effect of the rotation is to move the entire assembly including thedisc C to the left toward the motor housing, thus causing` the motor todrive through the planetary gear thereby provided at any suitablereduction, for cxampleat a reduction of three to one. As the rotor comesup -to speed the weights or shoes B3 are centrifugally moved outwardlyuntil their bevel or inclined surfaces B11 en ;a le the frictionalmembers C3 Vmounted on the disc C3. The result is to obtain a directdrive from theshaft A3,'since the shaft is secured .to the Vhub B, theWeights B3 rotate with the .hub B, and by their connection with thefrictional `member C3 directly drive the disc C3 and. through it thesleeve C3 and the pulley C3.

-Further, as the Weights are centrifusrallv .-movedand engage theopposed member C3 the inclination of the opposedengapging surfacestendito move the assembly which includes the disc CGto the right,roferrino; to Figure 1. This tends to disengage the frictional drivingmembers D3-from the fixed frictional 4member A3, thereby terminating1the planetary drive. As the planetary assembly is Withdrawn from contactwith the frictional member A3 the frictional member generally indicatedas E assumes its original position` the pin dropping; back to itsinitial location in relation -to the cam members El and the Vplanetarydriving, unitrotatcs -as an idle part of Ythe drivingY unit. In otherYWords once the ymotor'is rotating at speeds approaching its normal R.P. M., there is no rotation of the driving members D3 about the pins D1and no relative movement of the frictional momber E in relation to thedrive members D3.

, It can therefore be seen that not only have I provided an initialdriving o1` sta rti ng connection Which permits a. satisfactory startingtorque at minimum amperagre but l have provided such aconnection whichis in movementonly during vthe actual starting interval. Inasmuch as itis not in movement duringr normal operation oftheinotor, except as itrotates Withthe rotor as a Whole, wear is reduced to a minimum and thelife; of the moving membenislprolonged. Furthermore the employ .mentofthe -inclin'edsurfaces as vat B11 provides aegwedging or tighteningeffect which .clamps the members fixed and .prevents rattleandconsequent Wear. The starting device visthus silent,as Well 'aseicient and undesired relative movement of the parts during,` operationis prevented.

In normal operation the inside or stub shalt A3, When the motor hasreached a predetermined minimum speed, rotates in relation to the outersha'lt in ratio determined by the planetary gear reduction. By thismethod a starting' torque of 'four times the normal torque ot the motoris provided up to tour or live hundred R. l). M. Beyond this speed afull load torque ot' the motor is provided up to the full load speed.

l claim:

1. For use with an electric motor, a 'trictional starting` clutchincluding` a trietional drivinggear adapted to be driven by a motorshalt, a driven member tree to rotate in relation to said motor shatt,planetary friction gears associated with said driven meniber and adaptedfor engagement with said trictional driving` gear, a fixed trictionalmember asrociated with the motor and adapted to be en- `paneel by theplanetary gears, means responsive to the initial. rotation ot the motorslia'lft tor moving the frietional drivingv rear and planetarymembers-into operative drivin o' pe siti on and means etlective afterthe initiation of rotation lor withdrawing the planetary members fromContact ivitli the lifted trictional member.

2. The combination with an electric motor ot a starting clutch whichincludes a fixed gear member, a rotary ,gear member and a plurality otintermediate planetary gears, and means for 1withdrawing` said rotarynear men ber and planetary gears 'trom said lixed member in response torotation of the motor.

3. The combination with an electric motor of a starting' clutch whichincludes a tiXed `gear member, a rotary gear member and a plurality etintern'iediate planetary `desirs, and means tor withdrawingsaid rotary`gear member and planetary gears trom said lined member in response torotation ot' the motor, including' a centrifugal member associated Withtbe motor shaft and mounted ior movement in a plane substantiallyperpemlicular to the axis et rotation ot said shaft, said member beingprovided with a Wedding surface operative to Withdraw the rotary andplanetary gears` 4l. 'lhe combination ivitli an electric motor ot astarting' clutch which includes a fixed `rear mf-Jmber1 a rotary nearmeniber and a plurality ol intermediate plan ctary gears, and means 'torwithdrawing d roti l v, near member and planetary gears from said .tiredmember in response to rotation ot the motor, including a centrifugalmember associated with the motor shalt and mounted :for movement in aplane substantially perpei icular te the axis ot rotation et said shatt, sam centriliugal member beingr provided with cam dodging' tace, anda supportimr;r member for the 'intermediate planetary Lsears, saidsupporting member having' a portion opposed to said cam face, and in theplane of centriiugal movement of said centrifugal member.

5. The combination with an electric meter ot' a starting clutch whichincludes a ixed means :for .vitlidraiving` said rotary gear member andsaid planetary gear from operative association with said lined gearmember, in response to rotation of the motor.

(l. The combination with an electric motor et a starting; clutch whichincludes a lined gear member, a rotary `jear member, an intermediateplanetary gear adapted tor operative engagement with said fixed and saidrotary members and supporting means thereter, and centrilugally operablemeans tor withdrawing said rotary `gear member and said planetary `rearfrom operative association with said lined `gear men'iber, in responseto rotation et the motor, includinga centrifuojal Weight adapted toexert an outivardlj-,i wedding action upon said planetary `,earsupportingmeans.

7. The combination with an electric motor ot a startingv clutch whichincludes a fixed gear member, a rotary gear member, an inter mediateplanetary gear adapted tor operative enormement with said tired and saidrotary ,near members, and centritugally operable mean s tor withdrawingsaid rotan"v Oear member and said planetary gear trom operativeassociation with said lined rear member, in resoonse to rotation ot themotor, and independently operable means for withdrawing said rotary rearmember axially away from said iXed near member.

8. The combination with an electric motor of a starting clutch whichincludes a lifted lrear member, a rotary near member, an intermediateplanetary gear adapted for operative enga, rotary gear members, andcentriiugally operable means for ivi*lidraming;1 said rotary gear memberand said planetary gear trom operative association with said lined gearmember, in response to rotation oit the motor, and independentlyoperable means for Withdrawing` said rotary gear member axially awaylrom said lined gear member, including a cam member interposed betweenthe rotary L@gear member and the shaft ot the electric motor and a caniengaging member associated with the shaft.

9. The combination with an electric motor and motor shaft oil astartingr clutch which includes a tired gear member, a rotary gearmen'iber about said shaft, an intermediate planet-ary gear adapted foroperative engagement with said fixed rotary gear members and means Jforwithdrawing said rotary gear membe" and intermediate planetary gear mentwith said fixed and saidV from operative `association with said fixedgear member,V including Va cam memberv associated with said rotary gearmember and a cam engaging member Iassociated with said v shaft and heldagainst rotation in relation thereto, the rotary gear member beingrotatable in relation to said motor shaft through an arc snticient topermit a caming action therebetween.

l0. Qfhe structure or" claim 9 characterized in that the cam engagingmember is longitudinally movable along the motor shaft.

11. The structure ofclaim 9 characterized in that the cam engagingmember is longi- .15 tudinally movable Ialong the motor shaft,

and by the provision of yielding means tendingpnormally tomovethe camengaging member into Contact with .the opposed cam Vmember.

12. For use with an electric motor, a frictional starting clutchincluding a frictional vdrivinggear,adapted tobe driven by al motorshaft, a driven member free to rotate in relation to said motor shaft,planetary friction .26 gears ,associated With said driven member vandadapted for engagement with said frictional driving gear, a fixedfrictional member associated with the motor and adapted to be engaged bythe planetary gears, means resp'onsiveto the initial rotation ofthemotor yshattvfor .moving the i'rictional driving gear and planetarymembers into operaitve driving position and means effective after theinitiation of rotation for withdrawing the planetary members fromcontact With the rlined rictional member, including a centrifugal memberheld against rotation in relation to the motor shaft but movableradially, said centrifugal member being provided With v40 a wcdgingsurface adapted to engage an op- ,posedsurface upon the driven memberand to exert a `Wedging action thereagainst Where- ,by the planetarylmembers are Withdrawn v from,fcontact'vvith the `fixed frictional mem-.45 ber.

Signed at St. Louis, State of Missouri, this Y 21stday of March, 1929.

y LAURENCE M. PERSON-S.

